The present invention relates generally to laser instruments and, more particularly, to a method and apparatus for use with a laser scanner which projects a laser light beam in a scan pattern to facilitate finding a label on a package and reading the symbols on the label.
A wide variety of laser scanners have been designed to read bar code labels used on a broad range of retail packages for check-out and inventory purposes at the point of sale ("POS") for grocery stores and other high volume transaction businesses. One such laser scanner provided by the assignee of the present invention and disclosed in another patent application assigned to the assignee, U.S. Ser. No. 64,317 filed June 18, 1987, comprises an optical arrangement to project a laser light beam in a three-dimensional scan pattern through a window mounted flush with the surface of a counter top. The scan pattern is capable of finding and reading labels in as many orientations as possible. The basic requirement for using laser scanners at the point of sale is that the store check-out clerk, whether experienced or inexperienced, should not have to worry about the orientation of the label as the package is passed through the scan pattern.
When the window of the laser scanner is positioned vertically, the clerk must direct the package upwardly toward the window so that the scanner can read the label. It has been discovered that there is a very strong tendency for the clerk to check packages by passing the label horizontally across the window which prevents laser scanner from reading the label because it is not properly oriented in the scan pattern. Additionally the clerk has a more direct view of the inside of a vertically positioned scanner compared to a horizontal scanner since the clerk faces the window. As a result, the clerk is often distracted by the visible internal parts of the scanner. If the label is not properly oriented because of these problems, the clerk must repeat the scanning process as many times as necessary for the scanner to successfully read the label. As a result, the throughput time required to enter each product code into the POS terminal increases and, ultimately, the clerk becomes frustrated and reverts to hand-keying the product codes into the POS terminal which is unacceptable in such business environments.
Accordingly, there is a need to counteract the very strong tendency of the clerk to check packages by passing a bar code label horizontally past the window of the laser scanner and to further counteract the visual impact of the distraction of the clerk caused by the visible internal parts of the scanner.